We've all heard of going to extremes to lose weight, but a technique that came along this year was maybe one of the most extreme we have ever witnessed. And the pictures tell the whole story. Here's dan harris. Reporter: It is the extreme diets that got everybody talking. Wait till you see this. It is so disturbing. The diet that involved inserting a feeding untoo, the same procedure used to keep patients in a coma alive. Had did nuts. You feel like gagging. I couldn't watch that. I was like this the whole time. She saw the whole uproar and decided she wanted to try this diet. Can I give you my first impression? Sure. It looks incredibly uncomfortable. It's not. After three surgery she put on 30 pounds and says she tried everything to lose it. Even her own daughter was candid about it. You're really fat. When you first heard about this diet a feeding tube down into your belly, were you repulsed? I was repulsed a bit, but i wanted to know more. Reporter: Saavick linder, a chronic dieter, couldn't wait to try it, especially after the doctor told her she'd be back to work the same day. People's first reaction when they see me on the street is, "are you okay?" Reporter: Dr. Oliver DiPIETRO, AN INTERNIST IN Florida, is the only doctor in america who offers what's called the ke or feeding tube diet. When you first see someone with a feeding tube, it looks extreme. Well, I don't think the feeding tube diet is an extreme diet. Feeding tubes are very positive things. Reporter: The patients we spoke to say the procedure is painless. You just place this in the nose and I'm going to move it slowly. Ut still, it is hard to WATCH AS DR. DiPIETRO Demonstrates on his wife. Her nose, by the way, is anesthetized. Swallow, swallow. Reporter: Once the tube is in, it's connected to a pump which sends fluid from this bag into the stomach 24 hours a day for 10 straight days. The exact composition is a trade secret, but it is basically protein, certain fats and vitamins. The patients get 800 calories a day and they cannot ingest anything else except water, coffee and tea. That sends them into a state called ketosis where the body literally eats its own fat and some muscle for fuel. The patients have to keep the pump and the formula with them at all times. Lanell carries hers in a designer handbag. Saavviik has hers on her shoulder. Today I am on my eighth day, and as you can see, I am here at work. And I'm fine. Reporter: She's already lost 14 pounds. This is paolo commetto's second go round. Turn on your side. Reporter: Earlier this year he lost 20 pounds with the feeding tube and has kept it off, but he still wants to lose more. That's punishment. Just days after the tube goes in, he's grocery shopping with his wife. The first day is the toughest. Yeah, you're really hungry because you just started the diet but now -- you're not really hungry at all. Not really hungry. Just a mental thing, the smell. We're going to order. She's going to eat what i would want. Later it's dinner with family and friends. You're not eating. I am eating. This is my food. You see my food. The only time patients are allowed to disconnect the pump is ten minutes a day for bathing. They wear it to bed too. For this you pay $1500. The ads say you'll lose 20 pounds in ten days although there is a carefully placed asterisk there. When the feeding tube diet got its first burst of exposure this past april, some in the medical community including dr. David cass from yale university reacted with disgust and disapproval. You've usedwoushds like nonsense and appalling. There isn't the hope this would produce a lasting benefit. So this is in your view a moneymaking scheme. I think it's exploitation. I think on the part of the patients desperation breeds gullibility. I think, frankly, relying on a feeding tube is not all that different from relying on fingers down your throat to induce vomiting. It's the same kind of dysfunctional response to the whole relationship with food. It's unhealthy. Reporter: Now dr. Dipietro is responding to the criticism for the first time. He argues this is not some quick weight loss solution for brides, as was suggested in some of the initial media reports, but instead a serious new weapon in america's war on obesity. His point is that you are exploiting people's emotion and fear and despair over inability to lose weight for your own gain. What I would say to dr. Katz is I'm just offering the patients something that is safe and effective. It's been brought from europe. This is not something new. It's been around since 2005. So you can't call this exploitation. ♪ Reporter: This diet actually started over in italy, where tens of thousands of patients have been treated, including DR. DiPIETRO'S OWN WIFE, WHO IS Italian. At first I was totally against it. I thought it was baloney. I said, "listen, a feeding tube just too extreme." Reporter: His wife lost 18 pounds. Then the doctor tried it himself, and he lost 17 pounds. He was a convert. And he points to study results released this past may by the italian doctor who created the diet showing that 15,000 patients who went on the feeding tube managed to keep off 80% of the weight they lost for a year. This is evidence-based medicine. This is not voodoo medicine. This is not a fad. Reporter: Dr. Katz has reviewed the study, and he is utterly unconvinced. He points out it hasn't been vetted or published in a reputable journal. I have never seen methods used in this paper. It doesn't really rise to the standards of scientific evidence in 2012. Reporter: For lanell, who is planning on buying a new bikini and -- I'm in a skirt that I haven't been in for over three years. And bringing all of her older smaller clothing out of storage. I HAVE ALL MY SIZE 2s AND 4s Back in place. For her this debate is quite literally academic. This dress I haven't been able to fit in for four years. Absolutely in shock. Reporter: The knock on the diet is it's a gimmick -- no. Reporter: It won't last. No. Reporter: Are you confident, when tbe gets taken out today, that you'll be able to keep this weight off? Yes. A person who would do this for ten days, it's -- it's a commitment. I think you finally have the mind-set that you're ready to do it and you're doing it 100%. Let me check your weight. Okay, great. Reporter: Now it's time for the final weigh-in. 137. Okay. How are you? Reporter: And then good-bye to the feeding tube. Done, done. Blow your nose. Ooh. Back at home, she cleans out her closet. 20, 30 pounds of old clothes. And even though some doctors would advise her not to throw out those clothes, that she's likely to just put that weight back on, she is, for now, just reveling in her new, skinnier frame. You want that? Awesome. Give me a hug. Next -- these celebs tattooed for love. These everyday people did it for money to become human billboards. You've got a problem, boy. I hope they paid you well. But how much will it cost to take them off?

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